<?php

class OAuthException extends \Exception {
	//pass
}

/**
 * OAuth consumer对象，也对应于app。
 */
class OAuthConsumer {
	public $key;
	public $secret;

	function __construct($key, $secret, $callback_url=NULL) {
		$this->key = $key;
		$this->secret = $secret;
		$this->callback_url = $callback_url;
	}

	function __toString() {
		return "OAuthConsumer[key=$this->key,secret=$this->secret]";
	}
}

/**
 *	OAuth的token对，可以用于表示request token和access token
 *
 */
class OAuthToken {
	// access tokens and request tokens
	public $key;
	public $secret;

	/**
	 * key = the token
	 * secret = the token secret
	 */
	function __construct($key, $secret) {
		$this->key = $key;
		$this->secret = $secret;
	}

	/**
	 * generates the basic string serialization of a token that a server
	 * would respond to request_token and access_token calls with
	 */
	function to_string() {
		return "oauth_token=" .
		SHOAuthUtil::urlencode_rfc3986($this->key) .
           "&oauth_token_secret=" .
		SHOAuthUtil::urlencode_rfc3986($this->secret);
	}

	function __toString() {
		return $this->to_string();
	}
}

/**
 * 签名方法类，用于计算OAuth的签名
 * See section 9 ("Signing Requests") in the spec
 */
abstract class OAuthSignatureMethod {
	/**
	 * 返回签名方法 (比如 HMAC-SHA1)
	 * @return string
	 */
	abstract public function get_name();

	/**
	 * Build up the signature
	 * NOTE: The output of this function MUST NOT be urlencoded.
	 * the encoding is handled in OAuthRequest when the final
	 * request is serialized
	 * @param OAuthRequest $request
	 * @param OAuthConsumer $consumer
	 * @param OAuthToken $token
	 * @return string
	 */
	abstract public function build_signature($request, $consumer, $token);

	/**
	 * Verifies that a given signature is correct
	 * @param OAuthRequest $request
	 * @param OAuthConsumer $consumer
	 * @param OAuthToken $token
	 * @param string $signature
	 * @return bool
	 */
	public function check_signature($request, $consumer, $token, $signature) {
		$built = $this->build_signature($request, $consumer, $token);
		return $built == $signature;
	}
}

/**
 * The HMAC-SHA1 signature method uses the HMAC-SHA1 signature algorithm as defined in [RFC2104]
 * where the Signature Base String is the text and the key is the concatenated values (each first
 * encoded per Parameter Encoding) of the Consumer Secret and Token Secret, separated by an '&'
 * character (ASCII code 38) even if empty.
 *   - Chapter 9.2 ("HMAC-SHA1")
 */
class OAuthSignatureMethod_HMAC_SHA1 extends OAuthSignatureMethod {
	function get_name() {
		return "HMAC-SHA1";
	}

	public function build_signature($request, $consumer, $token) {
		$base_string = $request->get_signature_base_string();
		$request->base_string = $base_string;

		$key_parts = array(
		$consumer->secret,
		($token) ? $token->secret : ""
		);



		$key_parts = SHOAuthUtil::urlencode_rfc3986($key_parts);
		$key = implode('&', $key_parts);
		return base64_encode(hash_hmac('sha1', $base_string, $key, true));
	}
}

/**
 * The PLAINTEXT method does not provide any security protection and SHOULD only be used
 * over a secure channel such as HTTPS. It does not use the Signature Base String.
 *   - Chapter 9.4 ("PLAINTEXT")
 */
class OAuthSignatureMethod_PLAINTEXT extends OAuthSignatureMethod {
	public function get_name() {
		return "PLAINTEXT";
	}

	/**
	 * oauth_signature is set to the concatenated encoded values of the Consumer Secret and
	 * Token Secret, separated by a '&' character (ASCII code 38), even if either secret is
	 * empty. The result MUST be encoded again.
	 *   - Chapter 9.4.1 ("Generating Signatures")
	 *
	 * Please note that the second encoding MUST NOT happen in the SignatureMethod, as
	 * OAuthRequest handles this!
	 */
	public function build_signature($request, $consumer, $token) {
		$key_parts = array(
		$consumer->secret,
		($token) ? $token->secret : ""
		);

		$key_parts = SHOAuthUtil::urlencode_rfc3986($key_parts);
		$key = implode('&', $key_parts);
		$request->base_string = $key;

		return $key;
	}
}

/**
 * The RSA-SHA1 signature method uses the RSASSA-PKCS1-v1_5 signature algorithm as defined in
 * [RFC3447] section 8.2 (more simply known as PKCS#1), using SHA-1 as the hash function for
 * EMSA-PKCS1-v1_5. It is assumed that the Consumer has provided its RSA public key in a
 * verified way to the Service Provider, in a manner which is beyond the scope of this
 * specification.
 *   - Chapter 9.3 ("RSA-SHA1")
 */
abstract class OAuthSignatureMethod_RSA_SHA1 extends OAuthSignatureMethod {
	public function get_name() {
		return "RSA-SHA1";
	}

	// Up to the SP to implement this lookup of keys. Possible ideas are:
	// (1) do a lookup in a table of trusted certs keyed off of consumer
	// (2) fetch via http using a url provided by the requester
	// (3) some sort of specific discovery code based on request
	//
	// Either way should return a string representation of the certificate
	protected abstract function fetch_public_cert(&$request);

	// Up to the SP to implement this lookup of keys. Possible ideas are:
	// (1) do a lookup in a table of trusted certs keyed off of consumer
	//
	// Either way should return a string representation of the certificate
	protected abstract function fetch_private_cert(&$request);

	public function build_signature($request, $consumer, $token) {
		$base_string = $request->get_signature_base_string();
		$request->base_string = $base_string;

		// Fetch the private key cert based on the request
		$cert = $this->fetch_private_cert($request);

		// Pull the private key ID from the certificate
		$privatekeyid = openssl_get_privatekey($cert);

		// Sign using the key
		$ok = openssl_sign($base_string, $signature, $privatekeyid);

		// Release the key resource
		openssl_free_key($privatekeyid);

		return base64_encode($signature);
	}

	public function check_signature($request, $consumer, $token, $signature) {
		$decoded_sig = base64_decode($signature);

		$base_string = $request->get_signature_base_string();

		// Fetch the public key cert based on the request
		$cert = $this->fetch_public_cert($request);

		// Pull the public key ID from the certificate
		$publickeyid = openssl_get_publickey($cert);

		// Check the computed signature against the one passed in the query
		$ok = openssl_verify($base_string, $decoded_sig, $publickeyid);

		// Release the key resource
		openssl_free_key($publickeyid);

		return $ok == 1;
	}
}

class OAuthRequest {
	private $parameters;
	private $http_method;
	private $http_url;
	// for debug purposes
	public $base_string;
	public static $version = '1.0';
	public static $POST_INPUT = 'php://input';

	function __construct($http_method, $http_url, $parameters=NULL) {
		@$parameters or $parameters = array();
		$parameters = array_merge( SHOAuthUtil::parse_parameters(parse_url($http_url, PHP_URL_QUERY)), $parameters);
		$this->parameters = $parameters;
		$this->http_method = $http_method;
		$this->http_url = $http_url;
	}


	/**
	 * attempt to build up a request from what was passed to the server
	 */
	public static function from_request($http_method=NULL, $http_url=NULL, $parameters=NULL) {
		$scheme = (!isset($_SERVER['HTTPS']) || $_SERVER['HTTPS'] != "on")
		? 'http'
		: 'https';
		@$http_url or $http_url = $scheme .
                              '://' . $_SERVER['HTTP_HOST'] .
                              ':' .
		$_SERVER['SERVER_PORT'] .
		$_SERVER['REQUEST_URI'];
		@$http_method or $http_method = $_SERVER['REQUEST_METHOD'];

		// We weren't handed any parameters, so let's find the ones relevant to
		// this request.
		// If you run XML-RPC or similar you should use this to provide your own
		// parsed parameter-list
		if (!$parameters) {
			// Find request headers
			$request_headers = SHOAuthUtil::get_headers();

			// Parse the query-string to find GET parameters
			$parameters = SHOAuthUtil::parse_parameters($_SERVER['QUERY_STRING']);

			// It's a POST request of the proper content-type, so parse POST
			// parameters and add those overriding any duplicates from GET
			if ($http_method == "POST"
			&& @strstr($request_headers["Content-Type"],
                     "application/x-www-form-urlencoded")
			) {
				$post_data = SHOAuthUtil::parse_parameters(
				file_get_contents(self::$POST_INPUT)
				);
				$parameters = array_merge($parameters, $post_data);
			}

			// We have a Authorization-header with OAuth data. Parse the header
			// and add those overriding any duplicates from GET or POST
			if (@substr($request_headers['Authorization'], 0, 6) == "OAuth ") {
				$header_parameters = SHOAuthUtil::split_header(
				$request_headers['Authorization']
				);
				$parameters = array_merge($parameters, $header_parameters);
			}

		}

		return new OAuthRequest($http_method, $http_url, $parameters);
	}

	/**
	 * pretty much a helper function to set up the request
	 */
	public static function from_consumer_and_token($consumer, $token, $http_method, $http_url, $parameters=NULL) {
		@$parameters or $parameters = array();
		$defaults = array("oauth_version" => OAuthRequest::$version,
                      "oauth_nonce" => OAuthRequest::generate_nonce(),
                      "oauth_timestamp" => OAuthRequest::generate_timestamp(),
                      "oauth_consumer_key" => $consumer->key);
		if ($token)
		$defaults['oauth_token'] = $token->key;

		$parameters = array_merge($defaults, $parameters);

		return new OAuthRequest($http_method, $http_url, $parameters);
	}

	public function set_parameter($name, $value, $allow_duplicates = true) {
		if ($allow_duplicates && isset($this->parameters[$name])) {
			// We have already added parameter(s) with this name, so add to the list
			if (is_scalar($this->parameters[$name])) {
				// This is the first duplicate, so transform scalar (string)
				// into an array so we can add the duplicates
				$this->parameters[$name] = array($this->parameters[$name]);
			}

			$this->parameters[$name][] = $value;
		} else {
			$this->parameters[$name] = $value;
		}
	}

	public function get_parameter($name) {
		return isset($this->parameters[$name]) ? $this->parameters[$name] : null;
	}

	public function get_parameters() {
		return $this->parameters;
	}

	public function unset_parameter($name) {
		unset($this->parameters[$name]);
	}

	/**
	 * The request parameters, sorted and concatenated into a normalized string.
	 * @return string
	 */
	public function get_signable_parameters() {
		// Grab all parameters
		$params = $this->parameters;

		// Remove oauth_signature if present
		// Ref: Spec: 9.1.1 ("The oauth_signature parameter MUST be excluded.")
		if (isset($params['oauth_signature'])) {
			unset($params['oauth_signature']);
		}

		return SHOAuthUtil::build_http_query($params);
	}

	/**
	 * Returns the base string of this request
	 *
	 * The base string defined as the method, the url
	 * and the parameters (normalized), each urlencoded
	 * and the concated with &.
	 */
	public function get_signature_base_string() {
		$parts = array(
		$this->get_normalized_http_method(),
		$this->get_normalized_http_url(),
		$this->get_signable_parameters()
		);

		$parts = SHOAuthUtil::urlencode_rfc3986($parts);

		return implode('&', $parts);
	}

	/**
	 * just uppercases the http method
	 */
	public function get_normalized_http_method() {
		return strtoupper($this->http_method);
	}

	/**
	 * parses the url and rebuilds it to be
	 * scheme://host/path
	 */
	public function get_normalized_http_url() {
		$parts = parse_url($this->http_url);

		$port = @$parts['port'];
		$scheme = $parts['scheme'];
		$host = $parts['host'];
		$path = @$parts['path'];

		$port or $port = ($scheme == 'https') ? '443' : '80';

		if (($scheme == 'https' && $port != '443')
		|| ($scheme == 'http' && $port != '80')) {
			$host = "$host:$port";
		}
		return "$scheme://$host$path";
	}

	/**
	 * builds a url usable for a GET request
	 */
	public function to_url() {
		$post_data = $this->to_postdata();
		$out = $this->get_normalized_http_url();
		if ($post_data) {
			$out .= '?'.$post_data;
		}
		return $out;
	}

	/**
	 * builds the data one would send in a POST request
	 */
	public function to_postdata() {
		return SHOAuthUtil::build_http_query($this->parameters);
	}

	/**
	 * builds the Authorization: header
	 */
	public function to_header($realm=null) {
		$first = true;
		if($realm) {
			$out = 'Authorization: OAuth realm="' . SHOAuthUtil::urlencode_rfc3986($realm) . '"';
			$first = false;
		} else
		$out = 'Authorization: OAuth';

		$total = array();
		foreach ($this->parameters as $k => $v) {
			if (substr($k, 0, 5) != "oauth") continue;
			if (is_array($v)) {
				throw new OAuthException('Arrays not supported in headers');
			}
			$out .= ($first) ? ' ' : ",\n";
			$out .= SHOAuthUtil::urlencode_rfc3986($k) .
              '="' .
			SHOAuthUtil::urlencode_rfc3986($v) .
              '"';
			$first = false;
		}
		return $out;
	}

	public function __toString() {
		return $this->to_url();
	}


	public function sign_request($signature_method, $consumer, $token) {
		$this->set_parameter(
      "oauth_signature_method",
		$signature_method->get_name(),
		false
		);
		$signature = $this->build_signature($signature_method, $consumer, $token);
		$this->set_parameter("oauth_signature", $signature, false);
	}

	public function build_signature($signature_method, $consumer, $token) {
		$signature = $signature_method->build_signature($this, $consumer, $token);
		return $signature;
	}

	/**
	 * util function: current timestamp
	 */
	private static function generate_timestamp() {
		return time();
	}

	/**
	 * util function: current nonce
	 */
	private static function generate_nonce() {
		$mt = microtime();
		$rand = mt_rand();

		return md5($mt . $rand); // md5s look nicer than numbers
	}
}

class OAuthServer {
	protected $timestamp_threshold = 300; // in seconds, five minutes
	protected $version = '1.0';             // hi blaine
	protected $signature_methods = array();

	protected $data_store;

	function __construct($data_store) {
		$this->data_store = $data_store;
	}

	public function add_signature_method($signature_method) {
		$this->signature_methods[$signature_method->get_name()] =
		$signature_method;
	}

	// high level functions

	/**
	 * process a request_token request
	 * returns the request token on success
	 */
	public function fetch_request_token(&$request) {
		$this->get_version($request);

		$consumer = $this->get_consumer($request);

		// no token required for the initial token request
		$token = NULL;

		$this->check_signature($request, $consumer, $token);

		// Rev A change
		$callback = $request->get_parameter('oauth_callback');
		$new_token = $this->data_store->new_request_token($consumer, $callback);

		return $new_token;
	}

	/**
	 * process an access_token request
	 * returns the access token on success
	 */
	public function fetch_access_token(&$request) {
		$this->get_version($request);

		$consumer = $this->get_consumer($request);

		// requires authorized request token
		$token = $this->get_token($request, $consumer, "request");

		$this->check_signature($request, $consumer, $token);

		// Rev A change
		$verifier = $request->get_parameter('oauth_verifier');
		$new_token = $this->data_store->new_access_token($token, $consumer, $verifier);

		return $new_token;
	}

	/**
	 * verify an api call, checks all the parameters
	 */
	public function verify_request(&$request) {
		$this->get_version($request);
		$consumer = $this->get_consumer($request);
		$token = $this->get_token($request, $consumer, "access");
		$this->check_signature($request, $consumer, $token);
		return array($consumer, $token);
	}

	// Internals from here
	/**
	 * version 1
	 */
	private function get_version(&$request) {
		$version = $request->get_parameter("oauth_version");
		if (!$version) {
			// Service Providers MUST assume the protocol version to be 1.0 if this parameter is not present.
			// Chapter 7.0 ("Accessing Protected Ressources")
			$version = '1.0';
		}
		if ($version !== $this->version) {
			throw new OAuthException("OAuth version '$version' not supported");
		}
		return $version;
	}

	/**
	 * figure out the signature with some defaults
	 */
	private function get_signature_method(&$request) {
		$signature_method =
		@$request->get_parameter("oauth_signature_method");

		if (!$signature_method) {
			// According to chapter 7 ("Accessing Protected Ressources") the signature-method
			// parameter is required, and we can't just fallback to PLAINTEXT
			throw new OAuthException('No signature method parameter. This parameter is required');
		}

		if (!in_array($signature_method,
		array_keys($this->signature_methods))) {
			throw new OAuthException(
        "Signature method '$signature_method' not supported " .
        "try one of the following: " .
			implode(", ", array_keys($this->signature_methods))
			);
		}
		return $this->signature_methods[$signature_method];
	}

	/**
	 * try to find the consumer for the provided request's consumer key
	 */
	private function get_consumer(&$request) {
		$consumer_key = @$request->get_parameter("oauth_consumer_key");
		if (!$consumer_key) {
			throw new OAuthException("Invalid consumer key");
		}

		$consumer = $this->data_store->lookup_consumer($consumer_key);
		if (!$consumer) {
			throw new OAuthException("Invalid consumer");
		}

		return $consumer;
	}

	/**
	 * try to find the token for the provided request's token key
	 */
	private function get_token(&$request, $consumer, $token_type="access") {
		$token_field = @$request->get_parameter('oauth_token');
		$token = $this->data_store->lookup_token(
		$consumer, $token_type, $token_field
		);
		if (!$token) {
			throw new OAuthException("Invalid $token_type token: $token_field");
		}
		return $token;
	}

	/**
	 * all-in-one function to check the signature on a request
	 * should guess the signature method appropriately
	 */
	private function check_signature(&$request, $consumer, $token) {
		// this should probably be in a different method
		$timestamp = @$request->get_parameter('oauth_timestamp');
		$nonce = @$request->get_parameter('oauth_nonce');

		$this->check_timestamp($timestamp);
		$this->check_nonce($consumer, $token, $nonce, $timestamp);

		$signature_method = $this->get_signature_method($request);

		$signature = $request->get_parameter('oauth_signature');
		$valid_sig = $signature_method->check_signature(
		$request,
		$consumer,
		$token,
		$signature
		);

		if (!$valid_sig) {
			throw new OAuthException("Invalid signature");
		}
	}

	/**
	 * check that the timestamp is new enough
	 */
	private function check_timestamp($timestamp) {
		if( ! $timestamp )
		throw new OAuthException(
        'Missing timestamp parameter. The parameter is required'
        );

        // verify that timestamp is recentish
        $now = time();
        if (abs($now - $timestamp) > $this->timestamp_threshold) {
        	throw new OAuthException(
        "Expired timestamp, yours $timestamp, ours $now"
        	);
        }
	}

	/**
	 * check that the nonce is not repeated
	 */
	private function check_nonce($consumer, $token, $nonce, $timestamp) {
		if( ! $nonce )
		throw new OAuthException(
        'Missing nonce parameter. The parameter is required'
        );

        // verify that the nonce is uniqueish
        $found = $this->data_store->lookup_nonce(
        $consumer,
        $token,
        $nonce,
        $timestamp
        );
        if ($found) {
        	throw new OAuthException("Nonce already used: $nonce");
        }
	}

}

class OAuthDataStore {
	function lookup_consumer($consumer_key) {
		// implement me
	}

	function lookup_token($consumer, $token_type, $token) {
		// implement me
	}

	function lookup_nonce($consumer, $token, $nonce, $timestamp) {
		// implement me
	}

	function new_request_token($consumer, $callback = null) {
		// return a new token attached to this consumer
	}

	function new_access_token($token, $consumer, $verifier = null) {
		// return a new access token attached to this consumer
		// for the user associated with this token if the request token
		// is authorized
		// should also invalidate the request token
	}

}

class SHOAuthUtil {
	public static function urlencode_rfc3986($input) {
		if (is_array($input)) {
			return array_map(array('SHOAuthUtil', 'urlencode_rfc3986'), $input);
		} else if (is_scalar($input)) {
			return str_replace(
      '+',
      ' ',
			str_replace('%7E', '~', rawurlencode($input))
			);
		} else {
			return '';
		}
	}


	// This decode function isn't taking into consideration the above
	// modifications to the encoding process. However, this method doesn't
	// seem to be used anywhere so leaving it as is.
	public static function urldecode_rfc3986($string) {
		return urldecode($string);
	}

	// Utility function for turning the Authorization: header into
	// parameters, has to do some unescaping
	// Can filter out any non-oauth parameters if needed (default behaviour)
	public static function split_header($header, $only_allow_oauth_parameters = true) {
		$pattern = '/(([-_a-z]*)=("([^"]*)"|([^,]*)),?)/';
		$offset = 0;
		$params = array();
		while (preg_match($pattern, $header, $matches, PREG_OFFSET_CAPTURE, $offset) > 0) {
			$match = $matches[0];
			$header_name = $matches[2][0];
			$header_content = (isset($matches[5])) ? $matches[5][0] : $matches[4][0];
			if (preg_match('/^oauth_/', $header_name) || !$only_allow_oauth_parameters) {
				$params[$header_name] = SHOAuthUtil::urldecode_rfc3986($header_content);
			}
			$offset = $match[1] + strlen($match[0]);
		}

		if (isset($params['realm'])) {
			unset($params['realm']);
		}

		return $params;
	}

	// helper to try to sort out headers for people who aren't running apache
	public static function get_headers() {
		if (function_exists('apache_request_headers')) {
			// we need this to get the actual Authorization: header
			// because apache tends to tell us it doesn't exist
			$headers = apache_request_headers();

			// sanitize the output of apache_request_headers because
			// we always want the keys to be Cased-Like-This and arh()
			// returns the headers in the same case as they are in the
			// request
			$out = array();
			foreach( $headers AS $key => $value ) {
				$key = str_replace(
            " ",
            "-",
				ucwords(strtolower(str_replace("-", " ", $key)))
				);
				$out[$key] = $value;
			}
		} else {
			// otherwise we don't have apache and are just going to have to hope
			// that $_SERVER actually contains what we need
			$out = array();
			if( isset($_SERVER['CONTENT_TYPE']) )
			$out['Content-Type'] = $_SERVER['CONTENT_TYPE'];
			if( isset($_ENV['CONTENT_TYPE']) )
			$out['Content-Type'] = $_ENV['CONTENT_TYPE'];

			foreach ($_SERVER as $key => $value) {
				if (substr($key, 0, 5) == "HTTP_") {
					// this is chaos, basically it is just there to capitalize the first
					// letter of every word that is not an initial HTTP and strip HTTP
					// code from przemek
					$key = str_replace(
            " ",
            "-",
					ucwords(strtolower(str_replace("_", " ", substr($key, 5))))
					);
					$out[$key] = $value;
				}
			}
		}
		return $out;
	}

	// This function takes a input like a=b&a=c&d=e and returns the parsed
	// parameters like this
	// array('a' => array('b','c'), 'd' => 'e')
	public static function parse_parameters( $input ) {
		if (!isset($input) || !$input) return array();

		$pairs = explode('&', $input);

		$parsed_parameters = array();
		foreach ($pairs as $pair) {
			$split = explode('=', $pair, 2);
			$parameter = SHOAuthUtil::urldecode_rfc3986($split[0]);
			$value = isset($split[1]) ? SHOAuthUtil::urldecode_rfc3986($split[1]) : '';

			if (isset($parsed_parameters[$parameter])) {
				// We have already recieved parameter(s) with this name, so add to the list
				// of parameters with this name

				if (is_scalar($parsed_parameters[$parameter])) {
					// This is the first duplicate, so transform scalar (string) into an array
					// so we can add the duplicates
					$parsed_parameters[$parameter] = array($parsed_parameters[$parameter]);
				}

				$parsed_parameters[$parameter][] = $value;
			} else {
				$parsed_parameters[$parameter] = $value;
			}
		}
		return $parsed_parameters;
	}

	public static function build_http_query($params) {
		if (!$params) return '';

		// Urlencode both keys and values
		$keys = SHOAuthUtil::urlencode_rfc3986(array_keys($params));
		$values = SHOAuthUtil::urlencode_rfc3986(array_values($params));
		$params = array_combine($keys, $values);

		// Parameters are sorted by name, using lexicographical byte value ordering.
		// Ref: Spec: 9.1.1 (1)
		uksort($params, 'strcmp');

		$pairs = array();
		foreach ($params as $parameter => $value) {
			if (is_array($value)) {
				// If two or more parameters share the same name, they are sorted by their value
				// Ref: Spec: 9.1.1 (1)
				natsort($value);
				foreach ($value as $duplicate_value) {
					$pairs[] = $parameter . '=' . $duplicate_value;
				}
			} else {
				$pairs[] = $parameter . '=' . $value;
			}
		}
		// For each parameter, the name is separated from the corresponding value by an '=' character (ASCII code 61)
		// Each name-value pair is separated by an '&' character (ASCII code 38)
		return implode('&', $pairs);
	}
}

class OAuthUtil {
	public static $boundary = '';

	public static function urlencode_rfc3986($input) {
		if (is_array($input)) {
			return array_map(array('OAuthUtil', 'urlencode_rfc3986'), $input);
		} else if (is_scalar($input)) {
			return str_replace(
      '+',
      ' ',
			str_replace('%7E', '~', rawurlencode($input))
			);
		} else {
			return '';
		}
	}


	// This decode function isn't taking into consideration the above
	// modifications to the encoding process. However, this method doesn't
	// seem to be used anywhere so leaving it as is.
	public static function urldecode_rfc3986($string) {
		return urldecode($string);
	}


	public static function build_http_query($params) {
		if (!$params) return '';
		return http_build_query($params);
	}


	public static function build_http_query_multi($params) {
		if (!$params) return '';

		// Urlencode both keys and values
		$keys = array_keys($params);
		$values = array_values($params);
		$params = array_combine($keys, $values);

		// Parameters are sorted by name, using lexicographical byte value ordering.
		// Ref: Spec: 9.1.1 (1)
		uksort($params, 'strcmp');
		$pairs = array();
		self::$boundary = $boundary = uniqid('------------------');
		$MPboundary = '--'.$boundary;
		$endMPboundary = $MPboundary. '--';
		$multipartbody = '';

		foreach ($params as $parameter => $value)
		{
			if( in_array($parameter,array("pic","image")) && substr($value, 0, 1) == '@' )
			{
				$url = ltrim( $value , '@' );
				$content = file_get_contents( $url );
				$explode = explode( '?' , basename( $url ) );
				$filename = reset( $explode);
				$mime = self::get_image_mime($url);

				$multipartbody .= $MPboundary . "\r\n";
				$multipartbody .= 'Content-Disposition: form-data; name="' . $parameter . '"; filename="' . $filename . '"'. "\r\n";
				$multipartbody .= 'Content-Type: '. $mime . "\r\n\r\n";
				$multipartbody .= $content. "\r\n";
			}
			else
			{
				$multipartbody .= $MPboundary . "\r\n";
				$multipartbody .= 'content-disposition: form-data; name="'.$parameter."\"\r\n\r\n";
				$multipartbody .= $value."\r\n";
			}
		}
		$multipartbody .=  $endMPboundary;
		return $multipartbody;

	}
	public static function get_image_mime( $file )
	{
		$ext = strtolower(pathinfo( $file , PATHINFO_EXTENSION ));
		switch( $ext )
		{
			case 'jpg':
			case 'jpeg':
				$mime = 'image/jpg';
				break;

			case 'png';
			$mime = 'image/png';
			break;

			case 'gif';
			default:
				$mime = 'image/gif';
				break;
		}
		return $mime;
	}
}
?>
